问题 单项选择题

数据库的设计过程可以分为需求分析、概念设计、逻辑设计、物理设计四个阶段概念设计阶段得到的结果是________。

A.数据字典描述的数据需求

B.E-R图表示的概念模型

C.某个DBMS所支持的数据模型

D.包括存储结构和存取方法的物理结构

答案

参考答案:B

解析:本题考查数据库设计基本知识。数据库的设计过程可以分为需求分析、概念设计、逻辑设计和物理设计4个阶段。 在需求分析阶段,需求收集和分析,结果得到数据字典描述的数据需求和数据流图描述的处理需求。 在概念结构设计阶段,通过对用户需求进行综合、归纳与抽象,形成一个独立于具体DBMS的概念模型,可以用E—R图表示。E—R图表示的概念模型(概念设计),在逻辑结构设计阶段,将概念结构转换为某个DBMS所支持的数据模型(如关系模型),并对其进行优化。在物理设计阶段,为逻辑数据模型选取一个最适合应用环境的物理结构,包括存储结构和存取方法。

填空题
阅读理解

I will probably remember one June day seven years ago for the rest of my life. My father had been complaining that my brother and I were watching too much TV, but we ignored him. Then one day we came home and the television was gone.

When I asked my father about the missing TV, he said watching television was a waste of time. Without it, we would have time for other things.

I decided he was wrong. Is there life without TV? How can we spend the week without all those shows and soaps? I was sure my life would be boring without TV, I used my best debating skills to argue with him, but he would not give in.

However, I found other ways to spend my time finally, Each day I ran around the street. This reminded me of my love for athletics, which I still enjoy. I joined Volunteers, and I built lasting friendships. Most importantly, I discovered an artistic world I never knew. I started taking art contests, and was shocked when I won. Then I took piano lessons. I began to like listening to AM radio, reading news magazines.

Living without TV has taught me how to manage my time, so that I can do many things in one day. I am proud to have learned I don’t need television.

Looking back, I think my father did the right thing. “You are smart. You could do anything that you put your heart to.” he used to say. He believed in us. His actions showed me a much more colorful side of life without TV and the value of having a goal and sticking to it.

小题1:My father was angry and took the television away because _______.

A.we asked him to do so

B.my brother and I did not need it

C.he needed some money

D.my brother and I watched too much TV小题2:What did I do after the TV was missing?

A.I went to my friend’s house to watch TV.

B.I stayed at home all day.

C.I asked my father to buy a new television.

D.I did many useful things.小题3:_______ is NOT what I did after the TV was missing?

A.Running around the street

B.Sleeping day in and day out

C.Listening to the radio

D.Taking art contests小题4:The author mainly tells us that _______.

A.life without TV can be very colorful

B.life would be boring without TV

C.people can’t spend the week without shows and soaps

D.watching television was a waste of time